/*
 * Copyright (c) 2002, 2006, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 */
package com.sun.jmx.mbeanserver;

import java.util.logging.Level;

import javax.management.Attribute;
import javax.management.AttributeList;
import javax.management.AttributeNotFoundException;
import javax.management.DynamicMBean;
import javax.management.InvalidAttributeValueException;
import javax.management.JMRuntimeException;
import javax.management.MBeanAttributeInfo;
import javax.management.MBeanException;
import javax.management.MBeanInfo;
import javax.management.MBeanRegistration;
import javax.management.MBeanServer;
import javax.management.MBeanServerDelegate;
import javax.management.ObjectName;
import javax.management.ReflectionException;
import javax.management.RuntimeOperationsException;

import static com.sun.jmx.defaults.JmxProperties.MBEANSERVER_LOGGER;

/**
 * This class is the MBean implementation of the MBeanServerDelegate.
 *
 * @since 1.5
 */
final class MBeanServerDelegateImpl extends MBeanServerDelegate implements DynamicMBean, MBeanRegistration {

    final private static String[] attributeNames = new String[] { "MBeanServerId", "SpecificationName", "SpecificationVersion", "SpecificationVendor", "ImplementationName", "ImplementationVersion", "ImplementationVendor" };

    private static final MBeanAttributeInfo[] attributeInfos = new MBeanAttributeInfo[] { new MBeanAttributeInfo("MBeanServerId", "java.lang.String", "The MBean server agent identification", true, false, false), new MBeanAttributeInfo("SpecificationName", "java.lang.String", "The full name of the JMX specification " + "implemented by this product.", true, false, false), new MBeanAttributeInfo("SpecificationVersion", "java.lang.String", "The version of the JMX specification " + "implemented by this product.", true, false, false), new MBeanAttributeInfo("SpecificationVendor", "java.lang.String", "The vendor of the JMX specification " + "implemented by this product.", true, false, false), new MBeanAttributeInfo("ImplementationName", "java.lang.String", "The JMX implementation name " + "(the name of this product)", true, false, false), new MBeanAttributeInfo("ImplementationVersion", "java.lang.String", "The JMX implementation version " + "(the version of this product).", true, false, false), new MBeanAttributeInfo("ImplementationVendor", "java.lang.String", "the JMX implementation vendor " + "(the vendor of this product).", true, false, false) };

    private final MBeanInfo delegateInfo;

    public MBeanServerDelegateImpl() {
        super();
        delegateInfo = new MBeanInfo("javax.management.MBeanServerDelegate", "Represents  the MBean server from the management " + "point of view.", MBeanServerDelegateImpl.attributeInfos, null, null, getNotificationInfo());
    }

    final public ObjectName preRegister(MBeanServer server, ObjectName name) throws java.lang.Exception {
        if (name == null)
            return DELEGATE_NAME;
        else
            return name;
    }

    final public void postRegister(Boolean registrationDone) {
    }

    final public void preDeregister() throws java.lang.Exception {
        throw new IllegalArgumentException("The MBeanServerDelegate MBean cannot be unregistered");
    }

    final public void postDeregister() {
    }

    /**
     * Obtains the value of a specific attribute of the MBeanServerDelegate.
     *
     * @param attribute The name of the attribute to be retrieved
     *
     * @return  The value of the attribute retrieved.
     *
     * @exception AttributeNotFoundException
     * @exception MBeanException
     *            Wraps a <CODE>java.lang.Exception</CODE> thrown by the
     *            MBean's getter.
     */
    public Object getAttribute(String attribute) throws AttributeNotFoundException, MBeanException, ReflectionException {
        try {
            // attribute must not be null
            //
            if (attribute == null)
                throw new AttributeNotFoundException("null");

            // Extract the requested attribute from file
            //
            if (attribute.equals("MBeanServerId"))
                return getMBeanServerId();
            else if (attribute.equals("SpecificationName"))
                return getSpecificationName();
            else if (attribute.equals("SpecificationVersion"))
                return getSpecificationVersion();
            else if (attribute.equals("SpecificationVendor"))
                return getSpecificationVendor();
            else if (attribute.equals("ImplementationName"))
                return getImplementationName();
            else if (attribute.equals("ImplementationVersion"))
                return getImplementationVersion();
            else if (attribute.equals("ImplementationVendor"))
                return getImplementationVendor();

            // Unknown attribute
            //
            else
                throw new AttributeNotFoundException("null");

        } catch (AttributeNotFoundException x) {
            throw x;
        } catch (JMRuntimeException j) {
            throw j;
        } catch (SecurityException s) {
            throw s;
        } catch (Exception x) {
            throw new MBeanException(x, "Failed to get " + attribute);
        }
    }

    /**
     * This method always fail since all MBeanServerDelegateMBean attributes
     * are read-only.
     *
     * @param attribute The identification of the attribute to
     * be set and  the value it is to be set to.
     *
     * @exception AttributeNotFoundException
     */
    public void setAttribute(Attribute attribute) throws AttributeNotFoundException, InvalidAttributeValueException, MBeanException, ReflectionException {

        // Now we will always fail:
        // Either because the attribute is null or because it is not
        // accessible (or does not exist).
        //
        final String attname = (attribute == null ? null : attribute.getName());
        if (attname == null) {
            final RuntimeException r = new IllegalArgumentException("Attribute name cannot be null");
            throw new RuntimeOperationsException(r, "Exception occurred trying to invoke the setter on the MBean");
        }

        // This is a hack: we call getAttribute in order to generate an
        // AttributeNotFoundException if the attribute does not exist.
        //
        Object val = getAttribute(attname);

        // If we reach this point, we know that the requested attribute
        // exists. However, since all attributes are read-only, we throw
        // an AttributeNotFoundException.
        //
        throw new AttributeNotFoundException(attname + " not accessible");
    }

    /**
     * Makes it possible to get the values of several attributes of
     * the MBeanServerDelegate.
     *
     * @param attributes A list of the attributes to be retrieved.
     *
     * @return  The list of attributes retrieved.
     *
     */
    public AttributeList getAttributes(String[] attributes) {
        // If attributes is null, the get all attributes.
        //
        final String[] attn = (attributes == null ? attributeNames : attributes);

        // Prepare the result list.
        //
        final int len = attn.length;
        final AttributeList list = new AttributeList(len);

        // Get each requested attribute.
        //
        for (int i = 0; i < len; i++) {
            try {
                final Attribute a = new Attribute(attn[i], getAttribute(attn[i]));
                list.add(a);
            } catch (Exception x) {
                // Skip the attribute that couldn't be obtained.
                //
                if (MBEANSERVER_LOGGER.isLoggable(Level.FINEST)) {
                    MBEANSERVER_LOGGER.logp(Level.FINEST, MBeanServerDelegateImpl.class.getName(), "getAttributes", "Attribute " + attn[i] + " not found");
                }
            }
        }

        // Finally return the result.
        //
        return list;
    }

    /**
     * This method always return an empty list since all
     * MBeanServerDelegateMBean attributes are read-only.
     *
     * @param attributes A list of attributes: The identification of the
     * attributes to be set and  the values they are to be set to.
     *
     * @return  The list of attributes that were set, with their new values.
     *          In fact, this method always return an empty list since all
     *          MBeanServerDelegateMBean attributes are read-only.
     */
    public AttributeList setAttributes(AttributeList attributes) {
        return new AttributeList(0);
    }

    /**
     * Always fails since the MBeanServerDelegate MBean has no operation.
     *
     * @param actionName The name of the action to be invoked.
     * @param params An array containing the parameters to be set when the
     *        action is invoked.
     * @param signature An array containing the signature of the action.
     *
     * @return  The object returned by the action, which represents
     *          the result of invoking the action on the MBean specified.
     *
     * @exception MBeanException  Wraps a <CODE>java.lang.Exception</CODE>
     *         thrown by the MBean's invoked method.
     * @exception ReflectionException  Wraps a
     *      <CODE>java.lang.Exception</CODE> thrown while trying to invoke
     *      the method.
     */
    public Object invoke(String actionName, Object params[], String signature[]) throws MBeanException, ReflectionException {
        // Check that operation name is not null.
        //
        if (actionName == null) {
            final RuntimeException r = new IllegalArgumentException("Operation name  cannot be null");
            throw new RuntimeOperationsException(r, "Exception occurred trying to invoke the operation on the MBean");
        }

        throw new ReflectionException(new NoSuchMethodException(actionName), "The operation with name " + actionName + " could not be found");
    }

    /**
     * Provides the MBeanInfo describing the MBeanServerDelegate.
     *
     * @return  The MBeanInfo describing the MBeanServerDelegate.
     *
     */
    public MBeanInfo getMBeanInfo() {
        return delegateInfo;
    }

}
